U.S. patent number 5,074,042 [Application Number 07/576,210] was granted by the patent office on 1991-12-24 for shaver head with swivelling blade block.
This patent grant is currently assigned to Wilkinson Sword Gesellschaft mit beschrankter Haftung. Invention is credited to Wolfgang Althaus, Michael Schwarz.
United States Patent |
5,074,042 |
Althaus , et al. |
December 24, 1991 |
Shaver head with swivelling blade block
Abstract
The invention relates to a shaver head for a wet shaver. The
shaver head is arranged at the front end of a handle. A razor
blade, in the form of a single or double razor blade, is mounted in
the shaver head. The shaver head has a guide strip parallel to and
in front of the cutting edges of the razor blades. To achieve a
variation of the shaving angle and thus the cutting geometry in a
technically simple fashion, the razor blades are arranged in a
blade block which is swivelably mounted in relation to the
remainder of the body of the shaver head. The blade block is able
to swivel freely against a spring force about a swivelling axis
parallel to the cutting edges of the blades.
Inventors: |
Althaus; Wolfgang (Wuppertal,
DE), Schwarz; Michael (Herne, DE) |
Assignee: |
Wilkinson Sword Gesellschaft mit
beschrankter Haftung (Solingen, DE)
|
Family
ID: |
6842505 |
Appl.
No.: |
07/576,210 |
Filed: |
August 31, 1990 |
Foreign Application Priority Data
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Sep 2, 1989 [DE] |
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8910490[U] |
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Current U.S.
Class: |
30/50; 30/57 |
Current CPC
Class: |
B26B
21/227 (20130101) |
Current International
Class: |
B26B
21/08 (20060101); B26B 21/22 (20060101); B26B
021/02 () |
Field of
Search: |
;30/48,49,50,57,47,77 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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45879 |
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Feb 1982 |
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EP |
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2421662 |
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Dec 1974 |
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DE |
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3019399 |
|
Apr 1981 |
|
DE |
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3218411 |
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Dec 1982 |
|
DE |
|
Primary Examiner: Yost; Frank T.
Assistant Examiner: Payer; Hwei-Siu
Attorney, Agent or Firm: Robert W. Becker &
Associates
Claims
We claim:
1. A shaver head for a wet shaver, comprising:
at least one razor blade having a cutting edge;
a plastic body including a guide strip and a plastic blade block
for supporting said at least one razor blade, said blade block
being swivelably mounted in relation to the remainder of the body
and including a cover cap portion above said at least one razor
blade and a swivelling axis extending through the cover cap portion
parallel to the cutting edge; and
at least one spring disposed between the blade block and the
remainder of the body in a region proximate to said at least one
razor blade, for biasing the blade block relative to the remainder
of the body and for permitting the blade block to swivel against
the spring about the swivelling axis, to change the cutting
geometry and shaving angle in response to the force exerted on the
shaver by a user during shaving.
2. The shaver head of claim 1, wherein the blade block includes two
outside surfaces generally converging at a vertex and the
swivelling axis extends through the cover cap in a region proximate
to the vertex.
3. The shaver head of claim 1, wherein the blade block includes two
outside surfaces generally converging at a vertex and the
swivelling axis extends through the cover cap essentially in a
region below the vertex.
4. The shaver head of claim 1, wherein the body includes a pair of
side walls and said blade block is mounted swivelably in the side
walls of the body.
5. The shaver head of claim 4, wherein the blade block has a pair
of lateral pins which form the swivelling axis, and each of the
side walls include a recess therein, wherein the lateral pins are
swivelably mounted within said recesses.
6. The shaver head of claim 4, wherein the side walls of the body
each include an inner surface and the blade block includes a pair
of lateral wings each having an outer surface, the outer surfaces
forming together with the inner surfaces, guide surfaces for the
swivelling movement.
7. The shaver head of claim 6, wherein a stop is constructed
between each of the lateral wings of the blade block and the side
walls of the body.
8. The shaver head of claim 1, wherein at least one stop is
provided between the blade block and the body.
9. The shaver head of claim 1, wherein the guide strip comprises a
friction reducing polymeric slide strip parallel to the cutting
edge.
10. The shaver head of claim 1, wherein the at least one razor
blade is permanently embedded in the blade block.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a shaver head for a wet shaver.
The shaver head includes a razor blade and is arranged at the front
end of a handle. The shaver head also includes a guide strip
parallel to and in front of the cutting edge of the razor
blade.
2. Description of Related Art
Conventional shaver heads for a wet shaver are arranged at the
front end of a handle and include a single or double razor blade,
which is covered by a cover cap. A guide strip is arranged parallel
to and in front of the cutting edges of the razor blades.
In such a shaver head, the shaving geometry, and thus the shaving
angle, are defined by the front guide strip, the rear cover cap and
the cutting edges of the razor blades. However, these parts are
fixed to one another, resulting in a completely predetermined
shaving geometry and shaving angle, upon which the shaving
properties depend. It is desirable, however, for the user to be
able to vary the shaving geometry, and thus the shaving angle in
accordance with his requirements.
SUMMARY OF THE INVENTION
It is an object of the present invention to develop a shaver head
of a wet shaver type in such a way that a variation of the shaving
angle and cutting geometry is possible in a technically simple
fashion.
To achieve these objects the invention provides at least one razor
blade arranged in a blade block which is mounted in relation to the
remainder of the body of the shaver head. The blade block is
capable of swivelling against a biasing force about a swivelling
axis parallel to the cutting edge of the razor blade.
Accordingly, the shaving angle and thus the shaving geometry can be
varied in a technically simple fashion. This is achieved according
to the invention when, during shaving, the blade block carrying the
razor blades is swivelled inwards in accordance with the pressure
exerted by the user. In this way a simple variation of the shaving
angle is facilitated. When the compressive force diminishes, the
blade block with razor blade returns to its initial position.
Consequently, the shaver head according to the present invention
guarantees an overall improvement in shaving properties, since the
entire blade block can be swivelled at a certain angle relative to
the guide strip.
Preferably, the swivelling axis extends behind the cutting edge and
the blade block is mounted so as to be able to swivel downwards
into the body in the region between the swivelling axis and the
guide strip. Consequently, the greater the pressure applied, the
more the blade block is swiveled, and the smaller the shaving angle
becomes.
Advantageously, the uppermost razor blade is covered by a cover cap
through which the swivelling axis extends. In this way, the blade
block is suspended to swing to a certain extent in the remainder of
the body of the shaver head. Optimum conditions of leverage can
thus be achieved.
In this arrangement, the swivelling axis preferably extends
essentially in the region below the vertex of the cover cap.
In order to create in a structurally simple and inexpensive fashion
a swivel bearing for the blade block, the bearing is preferably
mounted swivelably in side walls of the body. The blade block
preferably has lateral pins, which define the swivelling axis. The
pins are swivelably mounted in corresponding recesses in the side
walls of the body. Overall only two parts are required for the
shaver head. The parts including a base body for housing the razor
blade unit and a single-piece blade block in which the razor blades
are embedded on plastic. The body is in the form of a single-piece
plastic body and includes a guide strip. When the shaver head is
assembled the blade block is inserted into the body, preferably
from above. The two parts engage by virtue of the pins of the blade
block, which snap into the corresponding recesses in the side walls
of the body.
The blade block has lateral wings which include outer surfaces,
which define guide surfaces for the swivelling movement of the
blade block in conjunction with inner surfaces of the body. The
inner surfaces of the body correspond to lateral wings of the side
walls of the body. In this manner, a perfect swivelling movement of
the blade block relative to the remainder of the body of the shaver
head is ensured.
Stops are preferably provided between the blade block and the body
to limit the movement of the blade block in predetermined, defined
positions. Preferably, the stops are constructed between the
lateral wings of the blade block and the side walls of the
body.
To further improve shaving properties, the shaver head is
preferably provided with a friction-reducing slide strip based, in
particular, on water-soluble or water-insoluble polymers. The
reduction of friction has the advantage that the shaving properties
of the shaver head are improved.
The shaver head with a swivelable blade block according to the
present invention can be used on any type of wet shaver. Thus, for
example, the razor blades can be exchangeable. In a preferred
embodiment, however, the shaver head is formed by a razor blade
unit in which the razor blades are permanently embedded in the
plastic blade block.
It is to be understood that both this general description and the
following detailed description are exemplary and explanatory only
and are not restrictive of the invention as claimed.
BRIEF DESCRIPTION OF THE DRAWINGS
The accompanying drawings which are incorporated in and constitute
a part of the specification illustrate an embodiment of the
invention, and together with the description serve to explain the
objects, advantages and principles of the invention.
FIG. 1 is a top view of the razor blade unit of the present
invention;
FIG. 2 is a side view of the razor blade unit;
FIG. 3 is a partial cut away along the line III--III of FIG. 1.
FIG. 4 is partial cutaway along the line IV--IV of FIG. 1.
DESCRIPTION OF THE PREFERRED EMBODIMENT
An embodiment of the present invention will be described with
reference to the drawings.
A razor blade unit 1 consists of a body 2 made of plastic. Plastic
body 2 has a side wall 3 at each of its two ends. Furthermore, a
guide strip 4 is connected in one piece to the remaining part of
body 2 via webs 5. Guide strip 4 extends in the longitudinal
direction of the razor blade unit 1.
The razor blade unit 1 is provided to be arranged at the front end
of a handle (not shown) of a wet shaver. Conventional fastening
means (not shown) are provided on the body 2 of the razor blade
unit 1 for fastening the shaver head to the handle.
Razor blade unit 1 has a blade block 6, also made of plastic.
Embedded in blade block 6 are razor blades 7 in the form of a
double razor blade, whose cutting edges 8 extend parallel to the
guide strip 4. On the top side, the razor blades 7 are covered by a
cover cap portion 9 of the blade block 6. Laterally, the blade
block 6 respectively has a wing 10, which is received in a
corresponding recess in the respective side wall 3 of the body
2.
The blade block 6 can be swivelled in conjunction with its embedded
razor blades 7 inside the body 2 about a swivelling axis A,
parallel to the cutting edges 8. In this arrangement, the
swivelling axis A is located in the region of the vertex S of the
cover cap 9. In order to facilitate the swivelling movement of the
blade block 6 inside the body 2, the two wings 10 of the blade
block 6 each have outwardly directed pins 11, which define the
swivelling axis A. The insides surfaces of side wall 3 of body 2
each have a recess 12 to receive a pin 11. The top side of the side
wall 3 of the body 2 respectively further has a bevel 13, as is to
be seen, in particular, in the sectional representation in
accordance with FIG. 4. During assembly blade block 6 with pins 11
can be placed from above onto the bevels 13. After the blade block
6 has been pressed down, the side walls 3 of the body 2 give way
outwards, so that the pins 11 of the blade block 6 can be engaged
in the associated recesses 12 in the body 2.
As shown in FIG. 3, arranged between the body 2 and the blade block
6 is means for applying a spring force, spring 14. Spring 14 is in
the form of a helical spring, which tends to rotate the blade block
6 counterclockwise, and thus to swivel the razor blades 7 outward
into the position represented in FIG. 3. However, the fundamental
position of FIG. 3 is limited by the bearing of the upper arm 15 of
the blade block 6 on the top side of the body 2.
Spring 14 presses blade block 6 forward into the position
represented in FIG. 3. As a result, there is a completely
determined shaving geometry and shaving angle. During shaving, the
razor blade unit 1 comes to bear on the skin of the user, the user
naturally exerting a specific pressure on the razor blade unit 1.
Consequently, the blade block 6 is swivelled with its embedded
razor blades 7, in the direction of the arrow P against the force
of the spring 14, the swivelling angle depending upon the size of
the force exerted. Thus, the stronger the user presses the razor
blade unit 1 onto the skin when shaving, the more the blade block 6
is swivelled inward, and the cutting geometry and thus the shaving
angle vary correspondingly. In FIG. 3, the shaving angle is
relatively large, while after blade block 6 is swivelled inwardly
the angle is relatively small, so that overall it is possible to
match the shaving angle to the particular shaving requirements.
In order to attain a perfect swivelling movement between the blade
block 6 and the body 2, the outside surfaces of wings 10 of blade
block 6 form together with the inside surfaces of the side walls 3
of body 2, guide surfaces 16. The surfaces being adjacent to one
another in a parallel fashion. Furthermore, stops 17 are provided
between body 2 and blade block 6. Stops 17 limit the swivelling
angle of the blade block 6 with respect to the body 2, and are
formed in the region of the side walls 3 and wings 10.
The razor blade unit 1 according to the present invention has the
advantage that the entire blade block 6 can be swivelled by a
certain angle relative to the guide strip 4. Thus, shaving geometry
can be varied with the shaving angle, so that overall the shaving
properties of the razor blade unit 1 are improved.
As illustrated in FIG. 3, the swivelling axis A is located in the
region of the vertex S of the cover cap 9. This arrangement of the
swivelling axis A is purely by way of example, and the axis can
also assume a different position inside the body 2.
Other embodiments of the invention will be apparent to those
skilled in the art from consideration of the specification and
practice of the invention disclosed herein. It is intended that the
specification be considered exemplary only, with a true scope and
spirit of the invention being indicated by the following
claims.
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